Development of reliable and eco-friendly processes for synthesis of metallic nanoparticles is an important step in the field of application of nanotechnology. In this study, we report the synthesis of silver nanoparticles using the leaf extracts of Euphorbia hirta and Nerium indicum. Synthesized particles are characterized by UV - Spectrophotometer, SEM, FTIR and X- ray diffraction analysis. The Debye-Scherrer equation was used to calculate particle sizes and the average size of the silver nanoparticles synthesized by E.hirta was 31nm and by N.indicum was 29nm. Further the synthesized silver nanoparticles were tested against common bacterial pathogens.

On account of the high accuracy with which spectroscopic data are obtained, thermodynamic parameters estimated from these data are more reliable than those obtained by direct thermal measurements. Spectroscopic data of aluminum based diatomic gas molecules (AlO, AlH, AlD, AlF, AlC) and partition function theory have been used to evaluate the thermodynamical parameters in the temperature range 100 - 3000 0K. Equilibrium constants for astrophysically important chemical process have been calculated using partition function theory. It is noticed that for AlC the heat capacity decreases exponentially after the critical temperature 1200 0K.

Microbial diversity of soil and water samples collected from pyrochemicals exposed areas of Virdhunagar district (Tamil Nadu, India) was studied. Soil and water samples from cultivable area, waste land and city area of the same region were also studied for a comparative acount. There is a remarkable reduction in total heterotrophic bacterial population (THB) in pyrochemicals exposed soil and water samples (42 10(4) CFU/g and 5.6 10(4) CFU/ml respectively), compared to the THB of cultivable area soil and water samples (98 10(7) CFU/g and 38.6 10(7) CFU/ml). The generic composition the THB of the pyrochemicals exposed samples too exhibited considerable change compared to other samples. Pseudomonas sp. was the predominant one (41.6%) followed by Achromobacter sp. (25%) in pyrochemical exposed soil and Pseudomonas sp. was the predominant one (25%) in pyrochemical exposed water samples followed by Bacillus sp. (25%) and Micrococcus sp. (16.6%). It was observed that Cornybacterium sp. and Micrococcus sp. were absent completely in pyrochemical exposed soil and Achromobacter sp. was missing in the pyrochemical exposed water samples, which were present in the other samples. The outcome of this study clearly demonstrates that pollutants such as chemicals used in pyrotechniques affect the microbial biodiversity and suitable measures have to be taken to control the pollution level and to save biodiversity.